1. Field of the Invention
The present invention relates to an optical pickup actuator and an optical disc drive using the same, and more particularly, to an optical pickup actuator using plate coils and an optical disc drive using the optical pickup actuator.
2. Description of the Related Art
Optical disc drives generally include an optical pickup used to record or reproduce information on or from a disc that is rotated by a spindle motor. Such an optical pickup records information on a disc by radiating light onto the disc via an objective lens or reproduces information from the disc by receiving light reflected from the disc. The optical pickup includes an actuator to control the position of the objective lens so that light is radiated onto the correct position of the disc.
FIG. 1 illustrates a conventional optical pickup actuator. Referring to FIG. 1, the optical pickup actuator includes a blade 2 on which an objective lens 1 is mounted, a plurality of wires 7, which support the blade 2 so that the blade 2 moves around a holder 3, a pair of magnets 5, which are installed on a base 4, and plate coils 6, which are installed on both sides of the blade 2. Here, the plurality of magnets 5 and the plate coils 6 operate as electromagnetic driving units to drive the blade 2 in focusing and tracking directions and to control the position of the objective lens 1.
A plurality of pattern coils (not shown) are formed on the plate coils 6. Thus, when a current flows through the pattern coils, the plate coils 6 interact with the pair of magnets 5, thereby generating an electromagnetic force by which the blade 2 is driven. In the related art, instead of the plate coils 6, winding coils are wound around the blade 2 at predetermined positions. However, in order to make an optical pickup compact and light, plate coils are preferred.
Reference numeral 8 denotes printed circuit boards (PCBs) which are installed on the blade 2 to electrically connect the pattern coils of the plate coils 6 and the wires 7. Thus, a current is supplied from a power supply (not shown) through the wires 7 and the PCBs 8 to the plate coils 6.
However, when the PCBs 8 are additionally installed on the blade 2 to electrically connect the wires 7 and the plate coils 6, the number of parts increases and the weight of the blade 2, the driving body of the actuator, increases to about 40–50 mg. Thus, the sensitivity of the actuator decreases. Also, since the PCBs 8 are adhered onto both sides of the blade 2 using a bond, the number of steps to assemble the optical pickup actuator and the dimensions of the blade 2 increase. This affects secondary resonant characteristics such as rolling, pitching, and yawing angles of the actuator with direction consequences on the actuator.
In order to compensate for these disadvantages, a structure in which a blade forms a single body including wires has been proposed. However, the attachment of a plurality of thin wires onto the blade is quite difficult in view of designing a mold. Also, as is known, the secondary resonant characteristics of an actuator having the blade and wires of the single body structure are not much better.
Accordingly, an optical pickup actuator having a structure capable of solving the problems of the conventional actuator is requested.